Those killed included Mangudadatu's wife, his two sisters, journalists, lawyers, aides, and motorists who were witnesses or were mistakenly identified as part of the convoy.

Andal Ampatuan Sr. first came into prominence when President Corazon Aquino appointed him as Chief-of-Offices of Maganoy (now Shariff Aguak) in 1986 immediately after the People Power Revolution.

[12][13] With escalating tensions in the province, Arroyo, as head of Lakas-Kampi-CMD, mediated between the Ampatuans and the Mangudadatus (both are from the same party) to prevent election-related violence.

Arroyo's adviser for political affairs, Gabriel Claudio, disclosed that there was an initial agreement "in principle" that no Mangudadatu would contest Ampatuan Sr.'s governorship.

[14] Buluan Vice Mayor Esmael "Toto" Mangudadatu had invited 37 journalists to cover the scheduled filing of his certificate of candidacy (COC) at the Commission on Elections (COMELEC) provincial office in Shariff Aguak.

He said reports had reached him that his rivals had threatened to chop him into pieces once he filed his COC, and felt the presence of journalists would deter such an attack.

Rather, he would send an all-women party led by his wife, two sisters, and an aunt with female lawyers, in order to file his COC on his behalf.

[17] At 9:30 am, a convoy carrying the journalists, lawyers, and relatives of Mangudadatu left Buluan to file his COC at the COMELEC office in Shariff Aguak.

At around 10:00 am, the convoy was passing through the town of Ampatuan when it stopped at a police checkpoint in Barangay Masalay, about 10 km from Shariff Aguak (four in other versions), for a routine inspection.

[9] On November 24, the president of the Philippines Gloria Macapagal Arroyo responded to the news of the massacre by declaring a state of emergency in Maguindanao, Sultan Kudarat and Cotabato City.

[29] Speaker of the House Prospero Nograles called on the police to quickly identify the perpetrators of the massacre and disarm private armies.

[33] On Wednesday, November 25, 2009, the executive committee of the Lakas-Kampi-CMD political party unanimously voted to expel three members of the Ampatuan family – Maguindanao Gov.

[8] On Thursday, November 26, 2009, Ampatuan Jr. surrendered to his brother Zaldy, was delivered to adviser to the peace process Jesus Dureza, then was flown to General Santos on his way to Manila, where he was taken to the National Bureau of Investigation (NBI) headquarters.

1959, President Gloria Macapagal Arroyo officially placed Maguindanao province under a state of martial law, thereby suspending the privilege of the writ of habeas corpus.

[40] Executive Secretary Eduardo Ermita said the step was taken in order to avert the escalation of "lawless" violence in the province and pave the way for the swift arrest of the suspects in the massacre.

Philippines National Police seized several armored personnel carriers, over a thousand military weapons including machine guns, assault and sniper rifles, sub-machine guns, shotguns, pistols, mortar launchers and rounds, grenades, rocket launchers, and caches of ammo and several military uniforms in one house, several buried weapons, ammo and COMELEC IDs in a vacant lot, rifles, shotguns, pistols, machine guns, SMGs and ammo, explosives and military uniforms in Zaldy's house.

The raids yielded weapons powerful enough to arm a battalion of soldiers, and ammo crates bearing the name of Department of National Defense (Philippines).

"[53] Andal Ampatuan Sr. was arraigned in a special court inside a Manila maximum-security prison on June 1, 2011, 18 months after he and a dozen family members were arrested over the killings.

[58] In November 2012, acting on a motion filed by Andal Ampatuan Jr., the Supreme Court set guidelines disallowing the live media broadcast of the trial but allowing the filming of the proceedings for real-time transmissions to specified viewing areas and for documentation.

The statement also expressed that Baraan and the panel of prosecutors had the full trust and support of Justice Secretary Leila De Lima.

[62] Also in August 2014, several teams of defense lawyers representing the accused withdrew from the case, citing conflicts of interest among their clients and other reasons.

[65] In a landmark ruling reported on July 6, 2017, the special court handling the trial dismissed for lack of evidence the multiple murder case filed against three suspects: Kominie Inggo, Dexson Saptula and Abas Anongan.

55 others, including Datu Sajid Islam Ampatuan, brother of Zaldy and Andal Jr. and the mayor of Shariff Saydona Mustapha, Maguindanao, were acquitted.

[5] On November 16, 2010, the international non-governmental organization Human Rights Watch issued a 96-page report titled "They Own the People", charting the Ampatuans’ rise to power, including their use of violence to expand their control and eliminate threats to the family's rule.

In the film, 8 people, mostly journalists, were ambushed, killed and was believed to be buried under the orders of their town's mayor, by an inmate who is routinely released from prison to carry out assassinations.

[84] An upcoming adult animated documentary film 58th would similarly portrayed the massacre and the missing of the last victim that never found, directed by Carl Joseph Papa.

In her 761-page decision, Judge Jocelyn Solis-Reyes cited the findings of Dr. Dean Cabrera, a medico-legal officer from the Philippines National Police Crime Laboratory who conducted forensic science examinations on the women victims.